Flexible “Glass Fabric” Arm Band Converts Body Heat Into Electricity

Your body is full of an underutilized energy potential that can be harnessed to power wearable technology and smart watches. A flexible arm band, developed by Korean researchers at KAIST, soaks up wasted heat from your body and transforms it into electricity. While still in the works, the lightweight and flexible glass fabric-based thermoelectric (TE) generator could eventually be used to create self-powered mobile devices.

Byung Jin Cho, a professor of electrical engineering at KAIST is in charge of the team to develop the flexible, thermoelectric (TE) generator. The device is made by screen printing liquid-like pastes of n-type (Bi2Te3) and p-type (Sb2Te3) TE materials onto glass fabric. As a result, hundreds of TE dots are printed on the glass fabric with a thickness of hundreds of microns thick. When placed on the body, the band utilizes waste heat to generate power, similar in concept to how a photovoltaic panel takes the sun’s energy to make power.

The material is very flexible and can be bent many times and still generate power. With a temperature difference of 31 °F between human skin and the surrounding air, the band can produce around 40 mW electric power. This energy could be used to power a smart watch or other mobile devices with hopes that this type of technology could make the devices self-powered and sustainable. Eventually, the technology could even be scaled up to take advantage of other wasted heat in larger systems.

“Our technology presents an easy and simple way of fabricating an extremely flexible, light, and high-performance TE generator,” explains Professor Cho. “We expect that this technology will find further applications in scale-up systems such as automobiles, factories, aircrafts, and vessels where we see abundant thermal energy being wasted.”